An ingrown toenail occurs when the side of the nail grows into the surrounding skin, causing a break in the protective barrier of the foot. When this barrier is compromised, bacteria can enter the soft tissue and lead to an infection, a condition often referred to in a clinical setting as paronychia. Recognising the specific signs of an infection is essential for determining when home care is sufficient and when medical intervention becomes necessary to prevent further complications.
What We’ll Discuss in This Article
- Identifying the physical appearance of an infected toe
- Understanding the types of discharge and pus formation
- Recognising changes in skin temperature and colour
- Distinguishing between normal inflammation and bacterial infection
- Identifying signs that an infection is spreading
- Specific risks for patients with underlying conditions
Visual indicators of a localised toenail infection
The primary visual signs of an infected ingrown toenail include intense redness, swelling, and the presence of pus at the site where the nail meets the skin. The NHS provides detailed information on how to identify the common symptoms of an ingrown toenail. While a non-infected nail may appear slightly pink or tender, an infection typically causes the skin to look shiny, tight, and deep red. This change in colour is the result of increased blood flow to the area as the immune system attempts to combat invading bacteria.
In many cases, the skin around the nail fold becomes so swollen that it begins to grow over the edge of the nail plate. This is often accompanied by the formation of granulation tissue, which is a collection of new blood vessels and connective tissue. This tissue often looks like a small, red, and moist lump that may bleed easily if bumped. The swelling is usually confined to the toe initially, but it can make the digit feel significantly larger and heavier than the surrounding toes.
The presence and appearance of pus or discharge
An infected toenail will often produce pus, which is a thick fluid composed of dead white blood cells, debris, and bacteria. This discharge can vary in colour from white or creamy yellow to a darker green hue depending on the type of bacteria present. If you notice fluid leaking from the side of the nail or see a small blister filled with pus, it is a clear indicator that the body is fighting a localised infection.
The discharge may be constant, or it may only appear when pressure is applied to the toe. In some instances, the fluid may dry and form a crust around the edge of the nail, which can trap further bacteria underneath. It is also common for the toe to emit a noticeable odour when an infection is present. This scent is caused by the metabolic processes of the bacteria and is a distinct clinical sign that differentiates a simple ingrown nail from one that has become septic.
Changes in pain levels and physical sensations
Increased pain is a hallmark of an infected ingrown toenail, often manifesting as a persistent throbbing sensation that does not subside when the foot is at rest. In the early stages of a simple ingrown nail, the pain is usually sharp and occurs only when wearing tight shoes or when the toe is accidentally knocked. However, once an infection develops, the pressure from the accumulation of pus and the internal swelling causes a constant ache that can interfere with sleep.
The toe will also become extremely sensitive to even the lightest touch. This hypersensitivity occurs because the inflammatory response sensitises the local nerve endings. You may find that the weight of a bedsheet or a sock causes significant discomfort. This level of pain is typically much higher than the mild irritation associated with a standard nail growth issue and indicates that the underlying tissues are under significant stress from the infectious process.
Variations in skin temperature and texture
An infected toe will often feel significantly warmer than the rest of the foot due to the localised inflammatory response. This increase in temperature, known as calor, occurs because the body dilates local blood vessels to allow more immune cells to reach the site of the bacterial invasion. If you compare the temperature of the affected toe to the corresponding toe on the other foot, the difference is usually quite obvious.
The texture of the skin may also change, becoming firm or hard to the touch, a state referred to as induration. As the infection progresses, the skin can become stretched and appear translucent or glossy because of the fluid buildup underneath. If the infection is deep, the skin may feel tense, as if it is under high pressure. These tactile changes are important markers for clinicians when they are assessing the severity of the tissue involvement.
Indicators of a spreading or systemic infection
Clinical evidence suggests that an untreated nail infection can lead to more serious conditions like cellulitis if the bacteria move into the deeper layers of the skin. One of the most critical signs that an infection is spreading is the appearance of red streaks or lines extending from the toe up the foot or towards the ankle. This can indicate lymphangitis, which is the inflammation of the lymphatic vessels as they try to filter the infection.
If the redness on the skin begins to cover a larger area of the foot or if the swelling moves into the midfoot or ankle, the infection is no longer localised. Systemic signs can also develop, such as feeling generally unwell, experiencing shivers, or having a high temperature. These symptoms suggest that the body is struggling to contain the infection and require immediate medical evaluation to prevent the development of sepsis or bone infections.
Risks associated with underlying health conditions
Individuals with certain health conditions must be particularly vigilant about the signs of an infected toenail because their bodies may not signal the problem in the usual way. For example, people with diabetes may have peripheral neuropathy, which reduces their ability to feel pain or heat in their feet. This means they might not notice the throbbing pain or the warmth of an infection until it has reached a dangerous stage.
Poor circulation can also complicate the situation by preventing the immune system from delivering enough white blood cells to the toe to fight the bacteria. In these cases, even a minor infection can lead to skin ulcers or tissue death. For anyone with a compromised immune system or a history of circulatory issues, any sign of redness or swelling around a toenail should be treated with high priority to avoid long term damage to the foot.
Conclusion
Recognising the signs of an infected ingrown toenail early is vital for effective management and preventing the spread of bacteria. Key indicators include the presence of pus, persistent throbbing pain, and significant warmth or redness that may spread across the toe. Monitoring these symptoms closely helps ensure that the condition does not escalate into a more serious medical issue. If you experience severe, sudden, or worsening symptoms, call 999 immediately.
How can I tell the difference between inflammation and infection?
Inflammation usually involves some redness and pain when the nail is pressed, but an infection typically includes pus, a foul odour, and a constant throbbing ache even without pressure.
Is it normal for an ingrown toenail to bleed?
Minor bleeding can occur if the nail pierces the skin, but frequent or heavy bleeding often indicates the presence of granulation tissue caused by a prolonged infection.
What does green pus around a toenail mean?
Green discharge often suggests the presence of specific bacteria such as Pseudomonas, which requires professional medical assessment to ensure the correct treatment is provided.
Why does my infected toe feel like it is pulsing?
The pulsing or throbbing sensation is caused by the increased blood flow and pressure from fluid and pus buildup within the confined space of the toe.
Can a nail infection cause a fever?
Yes, if the infection begins to spread into the bloodstream or surrounding tissues, it can trigger a systemic immune response resulting in a high temperature.
Does the redness always stay on the toe?
In many cases the redness is localised, but if it begins to spread to the top of the foot or forms red lines, this is a sign that the infection is moving.
What should I do if the skin is growing over my nail?
This overgrowth is a common response to chronic irritation and infection, and it usually requires a clinician to safely manage the tissue and the underlying nail.
Authority Snapshot (E-E-A-T)
This article is designed to provide clear and factual information regarding skin health for the general public. The content is written by the Medical Content Team and has been reviewed by Dr. Stefan Petrov. He is a UK-trained physician with an MBBS and postgraduate certifications including Basic Life Support (BLS), Advanced Cardiac Life Support (ACLS), and the UK Medical Licensing Assessment (PLAB 1 & 2). He has hands-on experience in general medicine, surgery, anaesthesia, ophthalmology, and emergency care. Dr. Petrov has worked in both hospital wards and intensive care units, performing diagnostic and therapeutic procedures, and has contributed to medical education by creating patient-focused health content and teaching clinical skills to junior doctors.
